Characterization and storage stability of microencapsulated black jamun (Syzygium cumini) pulp extract via freeze drying

In the present investigation, the black jamun extract was used to prepare microcapsules by freeze-drying method with three different wall materials: maltodextrin, guar gum, and xanthan gum. The formed microcapsules were analyzed for different physicochemical properties. Moisture content and water activity were less than 6.50 g water/ 100 g and 0.38, respectively, indicating that the microbial activity can be restricted. The formed microcapsules were purple in color suggested by the positive values of color parameter "a". The hygroscopicity, solubility, and degree of caking for the microcapsules were found to be in the range of 11.14-15.77 g/100 g, 70.12%76.36%, and 22.31%-30.22%, respectively. The glass transition temperature was in the range of 88-135 degrees C for the formed microcapsules. The encapsulation efficiency, total anthocyanin content, and antioxidant activity were higher for the maltodextrinbased microcapsule that was found to be 71.88%, 6.01 C-3-G mg/g and 94.16% DPPH radical scavenging activity, respectively. Practical application Black jamun (Syzygium cumini) is a rich source of anthocyanin which is unstable due to light, oxygen and temperature. Moreover the fruit also contain health beneficial substances that are unstable at normal conditions. Therefore, the encapsulation method can improve the stability of the compounds and improve the release of active component in the microcapsule in food. Microencapsulation provide barrier to temperature, light and pH. In food industry microcapsules containing agricultural produce extract can be used for the fortification of food products in enhancing the nutritive value of the product while processing.